TestSuite: multi-template support in CORRADE_COMPARE_{AS,WITH}().

Now it is possible to write this:

    CORRADE_COMPARE_AS(a, b, std::pair<int, int>);
    CORRADE_COMPARE_AS(a, b, Compare::Container<std::map<int, int>>());

The documentation uses slightly different (GCC-style) syntax (named
varargs parameter) so the arguments are self-descriptive, but the
compiler sees perfectly standard C++.
Jenkins CI configuration.
Moved ArchLinux PKGBUILDs to package/archlinux.

They were messing up the project root way too much.
package: added Clang PKGBUILD.
doc: fixed Jenkins CLI command name.
Utility: don't overwrite COMPILE_FLAGS if BUILD_STATIC_PIC is enabled.

Made the tests crash on assertions (they should be handled gracefully
w/o aborting).
package: use ONLY ONE shallow Git clone in Jenkins CI.

Not sepearate clone and workspace for each configuration combination.
Why the hell is that default.
package: Jenkins cleanup.

 * More descriptive configuration names. That damn thing shows only the
   values and not the variables, thus having ON and OFF repeated five
   times doesn't help much.
 * Use -fPIC for building static libraries.
 * Install to filesystem/ subdirectory so we don't mess up the
   JENKINS_HOME.
package: work around Jenkins inability to use anything else than JUnit.

Why do I need a plugin to manually set "Test Failed" state?!
package: don't schedule building of depending projects in Jenkins.

Magnum has 64 targets and in many cases the rebuild is not needed.
package: retry with git pull if it fails.

Jenkins has absolutely useless support for sharing one git directory by
multiple configurations. It tries to do the pull from all the workers at
one time.
Utility: don't forget to enable -fPIC also for CorradeUtilityObjects.
package: force sequential builds in Jenkins.

Follow-up to dd263c4ee1acf3767cdfcaeb4fc4454206f0f181, which didn't help
at all.
Utility: update Resource documentation.

We are asserting for not found resources now.
Utility: test filename consistency.
Utility: properly test Resource compilation with empty files.

Compilation of the generated file fails with "error: zero-size array
'resourceData'".
Utility: fix Resource compilation with empty data.
package: compile in Release mode for Jenkins CI.

Might point out various compiler misoptimizations.
package: Build other configurations even if the tests don't pass.

More convenient for cases when the main compiler misoptimizes something
and others do not.
TestSuite: fixed class/struct mismatch in test.